2261
NGC 2261 is Hubble's Variable Nebula.
- Odd
- Composite
Where 2261 fits
Why 2261 is special
It visibly changes shape over weeks, because clouds near the illuminating star cast moving shadows across the nebula.
Factors & digit properties
- Divisors (8)
- 1, 7, 17, 19, 119, 133, 323, 2261
- Prime factorisation
- 7 × 17 × 19
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 2261
- Scientific notation
- 2.261 × 10^3
Roman numerals
M M C C L X I
Binary
1 0 0 0 1 1 0 1 0 1 0 1
1 × 2,048 + 0 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 1 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 2,261
Octal
4 3 2 5
4 × 512 + 3 × 64 + 2 × 8 + 5 × 1 = 2,261
Hexadecimal
8 d 5
8 × 256 + d × 16 + 5 × 1 = 2,261
Read as powers of two: 2,048 + 128 + 64 + 16 + 4 + 1 = 2,261.
In historical numeral systems
Egyptian
2 lotuses, 2 coils of rope, 6 hobbles, 1 stroke
2 × 1,000 + 2 × 100 + 6 × 10 + 1 × 1 = 2,261. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges + 7 vertical wedges (sixties place), 4 corner wedges + 1 vertical wedge (units place)
37 × 60 + 41 = 2261. Places are separated by a space on the tablet, with the higher place written first.
Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.
Other mathematical patterns
- Deficient number
Related numbers & connections
Both lie in Monoceros, and one changes visible shape within weeks as shadows move across it.
View 2264 →Other connections
- is associated with2264
why?
Strength 0.50, confidence "high".
Science
NGC 2261 is a reflection nebula illuminated by the variable star R Monocerotis. Obscuring material near the star casts shifting shadows, changing the nebula's appearance on timescales of weeks.
DocumentedSciencePeriod: 1783–
Common questions
Is 2261 a prime number?
No, 2261 is not prime.
What are the factors of 2261?
The factors of 2261 are 1, 7, 17, 19, 119, 133, 323, 2261.
What is 2261 in Roman numerals?
2261 in Roman numerals is MMCCLXI.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 15 July 2026